High pressure spectroscopy of heavily doped ruby

No abstract availabl

Simulation of a Solar Domestic Water Heater

It is useful to introduce a simulation program for function of a simple solar installation in summer days, which embrace way of consuming and various ambient parameters. Numerous simplifications are assumed for performing the simulation with the aid of simple calculators (for example Excell) during a single interval DT. The variations of thermal parameters are calculated with intervals (fractions DT). For simulation of function of the installation during 48 hours, 4 initial hours were ta-ken at 52/DT intervals of time. Designate initial instant T0 and interval DT (1 hour or its fraction 0,5, 0,25, … of hour), the instant T become successively T+DT

Piezoelectric spectroscopic studies of Zn

This paper presents results of experimental and theoretical piezoelectric studies of a group of mixed crystals of the type Zn1 - x - yBexMnySe. The fittings of theoretical to experimental amplitude and phase piezoelectric spectra were performed in a modified Jackson and Amer model. The influence of the surface treatment such as grinding, polishing and etching on the PZE spectra is analysed in the model of surface defects applied for the interpretation of the spectra for energies of photons below the energy gap of the crystal

Crucial role of chelatable iron in silver nanoparticles induced DNA damage and cytotoxicity

Damage to mitochondria and subsequent ROS leakage is a commonly accepted mechanism of nanoparticle toxicity. However, malfunction of mitochondria results in generation of superoxide anion radical (O2•-), which due to the relatively low chemical reactivity is rather unlikely to cause harmful effects triggered by nanoparticles. We show that treatment of HepG2 cells with silver nanoparticles (AgNPs) resulted in generation of H2O2 instead of O2•-, as measured by ROS specific mitochondrial probes. Moreover, addition of a selective iron chelator diminished AgNPs toxicity. Altogether these results suggest that O2•- generated during NPs induced mitochondrial collapse is rapidly dismutated to H2O2, which in the presence of iron ions undergoes a Fenton reaction to produce an extremely reactive hydroxyl radical (•OH). Clarification of the mechanism of NPs-dependent generation of •OH and demonstration of the crucial role of iron ions in NPs toxicity will facilitate our understanding of NPs toxicity and the design of safe nanomaterials